Dodge Durango (DN). Manual — part 422

(6) Identify the fluid in the cylinders (i.e. coolant,

fuel, oil, etc.).

(7) Make sure all fluid has been removed from the

cylinders.

(8) Repair engine or components as necessary to

prevent this problem from occurring again.

(9) Squirt engine oil into the cylinders to lubricate

the walls. This will prevent damage on restart.

(10) Install new spark plugs.
(11) Drain engine oil. Remove and discard the oil

filter.

(12) Install the drain plug. Tighten the plug to 34

N·m (25 ft. lbs.) torque.

(13) Install a new oil filter.
(14) Fill

engine

crankcase

with

the

specified

amount and grade of oil.

(15) Connect the negative cable to the battery.
(16) Start the engine and check for any leaks.

VALVE SERVICE

REFACING

NOTE: Valve seats that are worn or burned can be
reworked, provided that correct angle and seat
width are maintained. Otherwise the cylinder head
must be replaced.

NOTE: When refacing valves and valve seats, it is
important that the correct size valve guide pilot be
used for reseating stones. A true and complete sur-
face must be obtained.

(1) Using a suitable dial indicator measure the

center of the valve seat Total run out must not
exceed 0.051 mm (0.002 in).

(2) Apply a small amount of Prussian blue to the

valve seat, insert the valve into the cylinder head,
while applying light pressure on the valve rotate the
valve. Remove the valve and examine the valve face.
If the blue is transferred below the top edge of the
valve face, lower the valve seat using a 15 degree
stone. If the blue is transferred to the bottom edge of
the valve face, raise the valve seat using a 65 degree
stone.

(3) When the seat is properly positioned the width

of the intake seat must be 1.75 – 2.36 mm (0.0689 –
0.0928 in.) and the exhaust seat must be 1.71 – 2.32
mm (0.0673 – 0.0911 in.).

(4) Check the valve spring installed height after

refacing the valve and seat. The installed height for
both intake and exhaust valve springs must not
exceed 41.44 mm (1.6315 in.).

(5) The valve seat and valve face must maintain a

face angle of 44.5 – 45 degrees angle.

ENGINE TIMING—VERIFICATION

CAUTION: The 4.7L is a non free-wheeling design
engine. Therefore, correct engine timing is critical.

NOTE: Components referred to as left hand or right
hand are as viewed from the drivers position inside
the vehicle.

NOTE: The blue link plates on the chains and the
dots on the camshaft drive sprockets may not line
up during the timing verification procedure. The
blue link plates are lined up with the sprocket dots
only when re-timing the complete timing drive.
Once the timing drive is rotated blue link-to-dot
alignment is no longer valid.

Engine base timing can be verified by the following

procedure:

(1) Remove the cylinder head covers. Refer to the

procedure in this section.

(2) Using a mirror, locate the TDC arrow on the

front cover (Fig. 11). Rotate the crankshaft until the
mark on the crankshaft damper is aligned with the
TDC arrow on the front cover. The engine is now at
TDC.

Fig. 10 Valve Assembly Configuration

1 – VALVE LOCKS (3–BEAD)
2 – RETAINER
3 – VALVE STEM OIL SEAL
4 – INTAKE VALVE
5 – EXHAUST VALVE
6 – VALVE SPRING

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4.7L ENGINE

9 - 19

SERVICE PROCEDURES (Continued)

(3) Note the location of the V8 mark stamped into

the camshaft drive gears (Fig. 12). If the V8 mark on
each camshaft drive gear is at the twelve o’clock posi-
tion, the engine is at TDC on the exhaust stroke. If
the V8 mark on each gear is at the six o’clock posi-
tion, the engine is at TDC on the compression stroke.

(4) If both of the camshaft drive gears are off in

the same or opposite directions, the primary chain or
both secondary chains are at fault. Refer to Timing
Chain and Sprockets procedure in this section.

(5) If only one of the camshaft drive gears is off

and the other is correct, the problem is confined to
one secondary chain. Refer to Single camshaft tim-
ing, in this procedure.

(6) If both camshaft drive gear V8 marks are at

the twelve o’clock or the six o’ clock position the
engine base timing is correct. Reinstall the cylinder
head covers.

SINGLE CAMSHAFT TIMING

NOTE: to adjust the timing on one camshaft, pre-
form the following procedure.

(1) Using Chain Tensioner Wedge, special tool

8350, stabilize the secondary chain drive. For refer-
ence purposes, mark the chain-to-sprocket position
(Fig. 13).

(2) Remove the camshaft drive gear retaining bolt.
(3) Carefully remove the camshaft drive gear from

the camshaft.

(4) Re-index the camshaft drive gear in the chain

until the V8 mark is at the same position as the V8
mark on the opposite camshaft drive gear.

NOTE: When gripping the camshaft, place the pli-
ers on the tube portion of the camshaft only. Do not
grip the lobes or the sprocket areas.

(5) Using a suitable pair of adjustable pliers,

rotate the camshaft until the alignment dowel on the
camshaft is aligned with the slot in the camshaft
drive gear (Fig. 14).

CAUTION: Remove

excess

oil

from

camshaft

sprocket retaining bolt before reinstalling bolt. Fail-
ure to do so may cause over-torqueing of bolt
resulting in bolt failure.

(6) Position the camshaft drive gear onto the cam-

shaft, remove oil from bolt then install the retaining
bolt. Using Special Tools, Spanner Wrench 6958 with
Adapter Pins 8346 and a suitable torque wrench,
Tighten retaining bolt to 122N·m (90 ft. Lbs.) (Fig.
15) (Fig. 16).

(7) Remove special tool 8350.
(8) Rotate the crankshaft two full revolutions, then

reverify that the camshaft drive gear V8 marks are
in fact aligned.

(9) Install the cylinder head covers. Refer to Cylin-

der Head Cover in this section.

Fig. 11 Engine Top Dead Center (TDC) Indicator

Mark

1 – TIMING CHAIN COVER
2 – CRANKSHAFT TIMING MARKS

9 - 20

4.7L ENGINE

DN

SERVICE PROCEDURES (Continued)

Fig. 13 Securing Timing Chain Tensioners Using Timing Chain Wedge

1 – LEFT CYLINDER HEAD
2 – RIGHT CYLINDER HEAD

3 – SPECIAL TOOL 8350 WEDGE
4 – SPECIAL TOOL 8350 WEDGE

Fig. 12 Camshaft Sprocket V8 Marks

1 – LEFT CYLINDER HEAD
2 – RIGHT CYLINDER HEAD

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4.7L ENGINE

9 - 21

SERVICE PROCEDURES (Continued)

TIMING CHAIN—MEASURING WEAR

NOTE: This procedure must be performed with the
timing chain cover removed.

(1) Remove the timing chain cover. Refer to Timing

Chain Cover in this section for procedure.

(2) To determine if the secondary timing chains

are worn, rotate the engine clockwise until maximum
tensioner piston extension is obtained. Measure the
distance between the secondary timing chain ten-
sioner housing and the step ledge on the piston (Fig.
17). The measurement at point (A) must be less than
15mm (.5906 inches).

(3) If the measurement exceeds the specification

the secondary timing chains are worn and require
replacement. Refer to Timing Chain and Sprockets in
this section for procedure.

PISTONS—FITTING

BORE GAGE METHOD
(1) To correctly select the proper size piston, a cyl-

inder bore gauge, capable of reading in 0.003 mm
(.0001 in.) INCREMENTS is required. If a bore
gauge is not available, do not use an inside microme-
ter.

(2) Measure the inside diameter of the cylinder

bore at a point 49.5 mm (1-15/16 inches) below top of
bore. Start perpendicular (across or at 90 degrees) to
the axis of the crankshaft at point A and then take

an additional bore reading 90 degrees to that at point
B (Fig. 19).

(3) The coated pistons will be serviced with the

piston pin and connecting rod pre-assembled. Tin
coated pistons should not be used as replacements for
coated pistons.

(4) The coating material is applied to the piston

after the final piston machining process. Measuring
the outside diameter of a coated piston will not pro-
vide accurate results (Fig. 18). Therefore measuring
the inside diameter of the cylinder bore with a dial
Bore Gauge is MANDATORY. To correctly select the
proper size piston, a cylinder bore gauge capable of
reading in 0.003 mm (.0001 in.) increments is
required.

(5) Piston

installation

into

the

cylinder

bore

requires slightly more pressure than that required
for non-coated pistons. The bonded coating on the
piston will give the appearance of a line-to-line fit
with the cylinder bore.

Fig. 14 Camshaft Dowel To Sprocket Alignment

1 – ADJUSTABLE PLIERS
2 – CAMSHAFT DOWEL

Fig. 15 Camshaft Sprocket Installation—Left

Cylinder Head

1 – TORQUE WRENCH
2 – CAMSHAFT SPROCKET
3 – LEFT CYLINDER HEAD
4 – SPECIAL TOOL 6958 SPANNER WITH ADAPTER PINS 8346

9 - 22

4.7L ENGINE

DN

SERVICE PROCEDURES (Continued)